1. Field of the Invention
The present invention relates to a matrix connector adapted for testing integrated circuits or circuit boards having high terminal density and more particularly, to such a matrix connector, which produces low contact stress, prevents deformation of solder balls, and allows a big tolerance of flatness of contact surface.
2. Description of the Related Art
The terminals of conventional integrated circuits are commonly made of metal. Therefore, the terminals of conventional integrated circuits have good mechanical strength, and test connectors can be electrically connected to the terminals of integrated circuits by clamping. An integrated circuit having metal terminals can be electrically connected to the internal circuit of an electronic device by SMT or DIP.
In recent years, conventional integrated circuits are made having a high terminal density. Due to high terminal density, it is difficult to connect an integrated circuit with metal terminals to a circuit board by SMT or DIP in mass production. In order to overcome this problem, solder balls are used in integrated circuits to substitute for metal terminals. However, the use of solder balls to substitute for metal terminals complicates test of integrated circuits after packaging.
Because the surface of a solder ball has low mechanical strength and is soft, the terminals of a connector clamp on the solder balls of an integrated circuit may deform the solder balls or force the solder balls away from the integrated circuit.
A good matrix connector has at least the following two features:
1. It does not damage the terminals of the electronic device, allowing reuse of the electronic device.
2. Its terminals can be electrically positively connected to all terminals of the electronic device. An electronic device may have tens or hundreds of terminals. The connector must be electrically connected to all terminals of the electronic device, completing the circuit connection.
There is know a conventional test connector for integrated circuits, which has the terminals set for contacting solder balls from the bottom side. However, this design is not reliable because the terminal design may cause a shot circuit easily.
Therefore, it is desirable to provide a matrix connector that eliminates the drawbacks of the conventional designs.